App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 81 · 40 questions

Developer's tip (Box, list, place): A variable holds one value; a list holds many in order. Positions start at 0. push adds to the end; pop takes off the last item; length is how many items. On the phone: works offline, private. In the cloud: shared, any device, needs the internet.

1. 1.💾 What number does this code show?
   let coins = 7;
   coins = coins - 1;
   coins = coins + 1;
   show(coins);
2. 2.💾 Which works with no internet at all? (a) a cloud backup (b) data saved on the phone (c) a shared chat (d) a cloud leaderboard
3. 3.💾 What number does this code show?
   let songs = ["Rain", "Monsoon", "Stars"];
   songs.push("Sunrise");
   songs.push("Kites");
   show(songs.length);
4. 4.💾 What number does this code show?
   let stars = 8;
   stars = stars - 4;
   stars = stars + 4;
   show(stars);
5. 5.Which of these fits saving on the phone? (a) chat messages to friends (b) the sound on/off setting (c) a class leaderboard (d) a shared to-do list
6. 6.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
7. 7.💾 What number does this code show?
   let coins = 5;
   coins = coins - 3;
   coins = coins + 4;
   show(coins);
8. 8.💾 What number does this code show?
   let coins = 9;
   coins = coins - 8;
   coins = coins + 5;
   show(coins);
9. 9.💾 pop() takes off the last item. What does this code show?
   let friends = ["Aman", "Kabir", "Meera", "Zoya"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Meera (b) Zoya (c) Aman (d) Kabir
10. 10.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Art", "Maths", "Science", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Art (c) Hindi (d) Maths
11. 11.💾 What number does this code show?
    let songs = ["Ocean", "Stars"];
    songs.push("Sunrise");
    show(songs.length);
12. 12.💾 What number does this code show?
    let notes = ["Maths", "Art", "Music", "Sports"];
    notes.push("Science");
    notes.push("Hindi");
    show(notes.length);
13. 13.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Kabir", "Zoya", "Arjun"];
    show(friends[1]); (a) Zoya (b) Kabir (c) Aman (d) Arjun
14. 14.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the phone is lost (c) the app is closed (d) you send a message
15. 15.💾 What number does this code show?
    let songs = ["Stars", "Ocean"];
    songs.push("Kites");
    show(songs.length);
16. 16.💾 Where should the app save the sound on/off setting: on the phone or in the cloud? (a) in the cloud (b) on the phone
17. 17.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Arjun", "Meera"];
    show(friends[2]); (a) Arjun (b) Meera (c) Zoya
18. 18.💾 What number does this code show?
    let notes = ["Science", "Art", "Maths"];
    notes.push("Sports");
    show(notes.length);
19. 19.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a list (d) a button
20. 20.💾 Where should the app save a shared to-do list: on the phone or in the cloud? (a) in the cloud (b) on the phone
21. 21.True or false: your last game level fits saving in the cloud. (a) False (b) True
22. 22.💾 What is a variable? (a) a phone setting (b) a picture (c) a type of screen (d) a named box for a value
23. 23.Which of these fits saving in the cloud? (a) your last game level (b) photos on two devices (c) notes to read offline (d) a draft you are typing
24. 24.💾 What number does this code show?
    let notes = ["Hindi", "Art", "Science", "Sports"];
    notes.push("Music");
    show(notes.length);
25. 25.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) your last game level (d) a class leaderboard
26. 26.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
27. 27.Which of these fits saving in the cloud? (a) a draft you are typing (b) a shared to-do list (c) the sound on/off setting (d) notes to read offline
28. 28.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Hindi", "Maths", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Hindi (c) Maths (d) Science
29. 29.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
30. 30.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
31. 31.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Rain", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Rain (c) Monsoon
32. 32.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
33. 33.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Sports", "Science", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Science (c) Sports (d) Music
34. 34.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
35. 35.💾 What number does this code show?
    let friends = ["Arjun", "Aman"];
    friends.push("Riya");
    show(friends.length);
36. 36.Which of these fits saving in the cloud? (a) a draft you are typing (b) the sound on/off setting (c) chat messages to friends (d) notes to read offline
37. 37.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
38. 38.Which of these fits saving on the phone? (a) chat messages to friends (b) notes to read offline (c) photos on two devices (d) a shared to-do list
39. 39.💾 What number does this code show?
    let notes = ["Hindi", "Music", "Science"];
    notes.push("Maths");
    show(notes.length);
40. 40.True or false: photos on two devices fits saving in the cloud. (a) True (b) False

Free app development lessons, practice and worksheets at talentjr.in/app-development-for-students